Using a water bath, melt pieces of chocolate in whipping cream. Add butter. After
chocolate and butter are melted, let mixture cool down.
Once mixture has somewhat hardened, whip it up, slowly adding rum. Using a pastry bag pipe
walnut-sized mounds onto a baking sheet lined with aluminum paper. Freeze for at least 30
minutes or until firm.
Using your hand, form the truffle into little balls and roll them in the cocoa powder.
(approximately 55 calories per piece).